File permissions reset after reboot
Question on Unix StackExchange
https://unix.stackexchange.com/questions/342991/linux-srv-directory-permissions-revert-on-reboot
Documentation
https://www.freedesktop.org/software/systemd/man/latest/systemd-tmpfiles.html?__goaway_challenge=meta-refresh&__goaway_id=712cf7dfe33d7ece2932a6168b51b2e8
If file permissions always resets after a reboot, systemd-tmpfiles is likely the reason.
Under /usr/lib/tmpfiles.d you'll find the regarding configfiles.
Edit them as needed.